JPH03204746A - Self-diagnostic system for dual shared memory - Google Patents

Abstract

PURPOSE:To secure the equivalent property of data of shared memories by executing the comparison with regard to data read out of the shared memories and diagnosing them at the time of write operation and at the time of read-out operation. CONSTITUTION:At the time of data write operation, a dual write mechanism 3 writes data in shared memories 1, 2, and thereafter, a dual read-out mechanism 4 reads out the data, respectively, and a data comparing mechanism 5 compares these read-out data and diagnoses its equivalent property. On the other hand, at the time of data read-out operation, the dual read-out mechanism 4 reads out the data from the shared memories 1, 2, respectively, and the data comparing mechanism 5 compares these read-out data and diagnoses its equivalent property. In such a way, at the time of write operation and at the time of read-out operation, the comparison is executed with regard to the data read out of the shared memories 1, 2 and they are diagnosed. Accordingly, the equivalent property of the data of the shared memories 1, 2 can be secured.

Description

[Detailed Description of the Invention] [Summary] Regarding a duplex shared memory self-diagnosis method that self-diagnoses the equivalence of data in a duplex shared memory, data read from the shared memory during a write operation and a read operation are compared, and the shared The purpose of this system is to diagnose and guarantee the equivalence of data in memory, and it is designed to provide dual shared memories, a dual write mechanism that writes data to these shared memories, a dual read mechanism that reads data from these shared memories, and a dual read mechanism that reads data from these shared memories. and a data comparison mechanism that compares data read from the shared memory by the mechanism, and after the duplex write mechanism writes data to the shared memory during a data write operation, the duplex read mechanism reads each data and compares the data. The a ellipse compares these read data to diagnose equivalence, while the duplex read mechanism reads data from the shared memory respectively during the data read operation, and the data comparison 8 Il structure compares these read data. Configure to diagnose equivalence.

[Industrial application field]

The present invention relates to a dual shared memory self-diagnosis method for self-diagnosing the equivalence of data in a dual shared memory. With the recent increase in the scale of information processing systems, duplicated shared memory has been adopted to integrate multiple computer systems. It is desired to guarantee the equivalence of this duplicated shared memory.

[Prior Art and Problems to be Solved by the Invention] Conventionally, as shown in FIG. 5, in a dual shared memory, data is simultaneously written to both shared memories 21 and 22 during a data write operation, and data is written to both shared memories 21 and 22 at the same time during a read operation. The data read from either is transferred to the access request source. As data is not compared during write and read operations, errors cannot be detected by the hardware. For example, if data cannot be written correctly to the shared memory 21 or 22 (an error in the data itself, an error in the write address). There is a problem in that duplication has no meaning at all when data is destroyed due to a multi-bit memory failure, etc.) or a multi-bit memory failure.

Furthermore, ′;J! The operation of the configuration shown in FIG. 25 will be briefly explained.

In FIG. 5, the shared memory access control mechanism 26 is
In response to an access request, the duplex write mechanism 23 is activated to write data to the shared memory 21.22, or the read mechanism 24 is activated to request access by reading data from either of the shared memories 21.22. I'm trying to transfer it back to the original. And shared memory 21,2
20. If a failure occurs in either one, the normal shared memory is accessed.

An object of the present invention is to compare data read from a shared memory during a write operation and a read operation to diagnose and guarantee the equivalence of data in the shared memory.

[Means to solve problems]

Means for solving the problem will be explained with reference to FIG.

In FIG. 1, shared memories 1 and 2 are duplicated shared memories.

The duplex write mechanism 3 is a mechanism for writing data into the shared memories I and 2.

The duplex read fim4 is a mechanism for reading data from the shared memory 1.2.

The data comparison mechanism 5 is a mechanism for comparing data read from the shared memory 1.2 by the duplex reading mechanism 4.

[Effect]

In the present invention, as shown in FIG.
After writing to e!, the redundant reading mechanism 4 reads the data respectively and compares the data. The horizontal 5 compares these read data and diagnoses the equivalence, while during the data read operation, the duplex read mechanism 4 reads data from the shared memory 1.2, and the data comparison mechanism 5 compares these read data. to diagnose equivalence.

Therefore, by comparing the data read from the shared memory 1.2 during the write operation and the read operation, it is possible to diagnose and guarantee the equivalence of the data in the shared memory 1.2.

〔Example〕

Next, the configuration and operation of one embodiment of the present invention will be explained in detail using FIGS. 1 to 4.

In FIG. 1, shared memories 1 and 2 are duplicated shared memories that can be shared and accessed by a plurality of computer systems.

The duplex writing mechanism 3 is a mechanism for writing data into the shared memory 1.2.

The write data buffer 3-1 is a buffer that temporarily stores data to be written to the shared memories L and 2.

The duplex reading mechanism 4 is a mechanism for reading data from the shared memories 1 and 2.

The data comparison mechanism 5 compares the data read from the shared memory 1.2 by the duplex reading mechanism 4. Also, during the write operation, the write data pants 73-
Compare the data (written data) stored in 1 with the read data.

The shared memory access control mechanism 6 activates the duplex write mechanism 3 or the duplex read mechanism 4 in response to an access request from an access request source to control data transfer with the access request source.

FIG. 2 shows an overall system configuration diagram of the present invention.

Here, the shared memory device 11 is a device according to the present invention and has the configuration shown in FIG. A total of a plurality of Xfa systems 12-1, 12-2, . . . 12n are systems that access the shared memory device 11 and execute processing while cooperating with each other.

Next, the control during the write operation in the configuration of FIG. 1 will be explained in detail using the flowchart of FIG.

In FIG. 3, ■ determines whether the mode is degenerate mode or not.

This determines whether the shared memory 1.2 in FIG. 1 is in degenerate mode. If YES (degenerate mode, that is, either shared memory 1 or shared memory 2 is normal)
In this case, the data is written to one of the shared memories with a value of 0, and the normal completion status is notified to the access request source.

On the other hand, in the case of No (not in the degenerate mode), the steps after ① are executed.

@ saves data in the write data buffer 11.

@ writes data to both shared memories 1 and 2.

(2) reads data from both shared memories 1.2.

(2) determines whether the data match. This determines whether or not the two data read in step (3) match. Y
In the case of ES, writing ends.

If NO, perform [phase].

[Phase] is compared with the contents of the write data buffer 3-1 to determine the failed shared memory. This compares the data saved in the write data buffer 3-1 in ■ with the data read from shared memory 1.2 in [phase], and detects shared memory 1.2 from which inconsistent data was read. shared memory.

(2) determines whether or not the shared memory 1.2 of both is in error. If YES, both shared memories 1 and 20 are in error, and the system will go down. In case of NO,
Execute [phase].

[Phase] sets shared memory to degenerate mode. This makes it difficult to disconnect the faulty shared memory, sets it in a degraded mode, and notifies the access requester to that effect.

As described above, data is transferred to the shared memory 1. during the write operation.
By diagnosing the equivalence of shared memory 1.2 by comparing the read data after writing to 2 and checking whether they match or not, the equivalence of shared memory 1 and 2 is constantly checked during a write operation. This makes it possible to guarantee that Also,
By comparing the data read from the shared memory 1.2 with the write data stored in the write data buffer 3-1, it becomes possible to easily find and disconnect the failed shared memory.

Next, the control during the read operation in the configuration shown in FIG. 1 will be explained in detail using the flowchart shown in FIG.

In FIG. 4, ■ determines whether or not the mode is degenerate mode.

This determines whether the shared memories 1 and 2 in FIG. 1 are in degenerate mode. If YES, data is read from one of the shared memories in [phase], the normal termination status is notified to the access request source, and the process ends. If NO, execute the steps from O onwards.

[Phase] reads data from both shared memories 1.2.

[Phase] determines whether the data match. YES
In the case of 0, the read data matches and is correct, so it is transferred to the access request source and the status of normal completion is notified. On the other hand, in the case of NO, the data read with @ does not match, so with [phase] the shared memory is set to failure mode, a failure log is collected, and the status of the hardware failure is notified to the access request source.

As described above, data corruption after writing can be detected and high reliability can be obtained by reading data from shared memory 1.2 during read operation and comparing it to determine whether it matches or not. becomes.

Note that the case where an error (error due to parity check or ECC check) is detected in the data read from shared memories 1 and 2 is not explained, but one of the shared memories in which this error was detected is separated and Set to retreat mode.

〔Effect of the invention〕

As explained above, according to the present invention, since a configuration is adopted in which diagnosis is performed by comparing data read from the shared memory 1.2 during a write operation and a read operation, the data in the shared memories 1 and 2 are compared. isodominance can be guaranteed. In particular, during a data write operation, by comparing the data read from both shared memories 1 and 2 after writing the data, high data guarantee can be obtained without software overhead. Also, during data read operation, both shared memories 1
．． By comparing the data read from 2, it is possible to detect data corruption after writing, and even higher reliability can be obtained.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of one embodiment of the present invention, and Fig. 25! J shows an overall system configuration diagram of the present invention, FIGS. 3 and 4 are flowcharts explaining the operation of the present invention, and FIG. 5 shows an explanatory diagram of the prior art. In the figure, l, 2 is shared memory, 3 is duplex writing mechanism, 3
-1 is a write data buffer, 4 is a duplex read mechanism,
5 is a data comparison mechanism, 6 is a shared memory access control mechanism, 11 is a shared memory device, and 12-1 to 12-n are computer systems.

Claims (1)

[Claims] A duplex shared memory self-diagnosis method for self-diagnosing the equivalence of data in duplex shared memories includes duplex shared memories (1) and (2), and these shared memories (1) and (2). A redundant write mechanism (3) that writes data to the shared memory (1), a redundant read mechanism (4) that reads data from these shared memories (1) and (2), and a redundant read mechanism (4) that writes data to the shared memory (1).
, (2), and after the duplex writing mechanism (3) writes data to the shared memories (1) and (2) during a data write operation, The duplex readout mechanism (4) reads each data, and the data comparison mechanism (5) compares these read data to diagnose equivalence. Meanwhile, during the data read operation, the duplex readout mechanism (4)
reads data from the shared memories (1) and (2), respectively, and the data comparison mechanism (5) compares the read data to diagnose equivalence. Self-diagnosis method.